Fine-tuning the scrubbing of derived objects

Suppose that the adjustment in the grace period is not enough to keep the disk partition from filling up. You might decide to run the scrubber utility more often: during the work day as well as overnight. To minimize the impact on users during the work day, you can pinpoint the scrubbing—perhaps to the DOs created in a particular directory.

This example shows the command-line syntax supported on Linux® or the UNIX® system, for moving a DO pool and scrubbing it more often:

  1. Determine the directory’s current DO storage pool assignment. You must clean up this storage pool.

    cd /vobs/sources

    cleartool describe –long reorg@@
    directory element "reorg@@":
      .
      .
      ...  derived pool: ddft

    This directory uses the default DO pool.
  2. Assign the directory to a separate storage pool. This assignment enables finer control of scrubbing, which can be invoked on a per-pool basis:

    cd /vobs/sources

    cleartool mkpool –derived new_do_pool
    Comments for "new_do_pool":
    pool for DOs created in /vobs/sources/reorg
    .
    Created pool "new_do_pool".cleartool chpool new_do_pool reorg
    Changed pool for "reorg" to "new_do_pool".

  3. Determine the location of the VOB storage directory. Use the lsvob command:

    cleartool lsvob /vobs/sources
    * /vobs/sources /net/mars/vobstg/sources.vbs

  4. Scrub the new storage pool thoroughly and often. There are many ways to accomplish this. You can create a new task for the scheduler that invokes the scrubber utility for your new pool. For example:

    scrubber –e –p new_do_pool /net/mars/vobstg/sources.vbs

    This script invokes the scrubber on the derived object storage pool new_do_pool. The –e option removes DOs with a reference count of zero. You can then register your task in the scheduler’s task database and create a new scheduled job to run the task several times per day. For more information about tasks and jobs, see The Rational ClearCase scheduler.
  5. Clean up the old DO storage pool. The chpool command in Step 2 does not move existing DO data containers; it affects only where a new DO’s data container is stored. Accordingly, the old storage pool should be cleaned up:

    ccase-home-dir/etc/scrubber –e –p ddft /net/mars/vobstg/sources.vbs

Parent topic: Adjusting default scrubbing parameters
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